First of all the Dothraki came from far east to where they are now almost 400 years ago. Nothing is known about them before this event.

How do the Dothraki make their weapons?

What material do they use? Do their razor sharp arakhs require superior quality steels?

Where do they find such steels and which smiths make their weapons?

Is it possible that the mother of mountains have rich iron mines suitable for making high quality weapons?

As a side note, I want to emphasize on the Ergenekon legend which is a (Mongol or Turkic) rebirth myth. In this legend, they suffer a great defeat and some younglings escape their enemise in guidance of a she-wolf. They come to a Vale hidden high in the mountains through a secret passage. They live there and reproduce for 400 years until the Vale cannot feed their great numbers. They cannot find the hidden passage their ancestors knew. A blacksmith offers to melt down rock to open a passage. They get out and claim their original lands by defeating their enemies.

I've always imagined arakhs being little like katanas. Because of lack of good steel, the dotharaki have invented other ways to make good blades. Correct me if I'm wrong, but I remember that katanas weren't made from exceptionally good metal at all - they were so sharp because of how they were made. The dotharaki have a great technique for making arakhs.

I highly doubt any mines. It's completely against what the dotharaki are. They're raiding Free Cities and trading at Slaver's Bay constantly. They surely get enough steel and iron through tributes and raiding, since they don't need gold.

I've always imagined arakhs being little like katanas. Because of lack of good steel, the dotharaki have invented other ways to make good blades. Correct me if I'm wrong, but I remember that katanas weren't made from exceptionally good metal at all - they were so sharp because of how they were made. The dotharaki have a great technique for making arakhs.

I highly doubt any mines. It's completely against what the dotharaki are. They're raiding Free Cities and trading at Slaver's Bay constantly. They surely get enough steel and iron through tributes and raiding, since they don't need gold.

You're right about katanas, the metal they were made out of is what we call pig iron, the folding thing they did was a way to leech the carbon out, bringing it closer to proper steel.

I've always imagined arakhs being little like katanas. Because of lack of good steel, the dotharaki have invented other ways to make good blades. Correct me if I'm wrong, but I remember that katanas weren't made from exceptionally good metal at all - they were so sharp because of how they were made. The dotharaki have a great technique for making arakhs.

I highly doubt any mines. It's completely against what the dotharaki are. They're raiding Free Cities and trading at Slaver's Bay constantly. They surely get enough steel and iron through tributes and raiding, since they don't need gold.

All Dothraki armed with high-quality steel weapons sounds like an ultimate fantasy, bigger than dragons.

In 16-18th centuries, many of Crimean Tatars had to arm themselves with sharp sticks and horse jaws roped to wooden handles for lack of steel weapons. Mind you, Crimean Tatars were only partly nomadic, they had permanent settlement areas too, the whole power of the Ottoman empire stood behind them (Crimea was vassal to Sublime Porte), and nonetheless.

So two things sound utterly crazy about Dothraki: their enormous numbers and their excellent weaponry.

Until modern techniques beginning in 1800's, steel was expensive even in our world. It was used when no alternative was present in those days. If the Dothraki are relying on foreign people for their weapons, it does not make sense because any disruption in trade would end their power. I think GRRM must give us more about their battle tactics and weaponcraft.

Well, I'd say European swords and Western martial arts in general are incredibly underrated.

Agreed.

Where does this "katanas are overrated" idea come from?

They are overrated. A katana cannot cut through a tree or steel. The force you would have to generate is impossible for such a feat no matter how sharp your blade is. The katana became a widely collected item for collectors and the sword has this sort of mythical standing among many people. Its a sword, not some sort of magical power weapon.

Until modern techniques beginning in 1800's, steel was expensive even in our world. It was used when no alternative was present in those days. If the Dothraki are relying on foreign people for their weapons, it does not make sense because any disruption in trade would end their power. I think GRRM must give us more about their battle tactics and weaponcraft.

Dotharaki don't trade. They get their riches from Free Cities as gifts or by raiding cities. They seem to trade slaves, though, but only to non-Dotharaki. Somehow I think there's already enough weapons in Dotharaki Sea for multiple armies.

They are overrated. A katana cannot cut through a tree or steel. The force you would have to generate is impossible for such a feat no matter how sharp your blade is. The katana became a widely collected item for collectors and the sword has this sort of mythical standing among many people. Its a sword, not some sort of magical power weapon.

With katanas I meant that dotharaki may posses techniques to make higher-quality blades from only iron than they could do normally.

I'd say they could have aqcuired the better quality arakhs as gifts. We know that if a dothraki horde comes calling behind your city walls, it's easier to try be friendly with them and exchange gifts. It's not that unthinkable to assume that at same point someone got the idea of gifting a khal with a mighty fine arakh to save the city from sacking, and others followed his lead.

Also, the dothraki have slaves, so it could be that among them are also some smiths, who, if given the proper tools, can provide the khalasar with weaponry without the dothraki ever taking up smithing themselves.